He's returning to England for family reasons, according to a statement from St George.
His results as a head coach aren't great, but he was at Wire, St George, and now Leeds in an assistant / member of the performance team capacity, not a head coach.
St George and Leeds would have no doubt done their due dilligance before hiring him - RL is a pretty small and well-connected sport - if he was as bad as social media and this forum makes out, he would have struggled to find work, yet oportunities keep presenting themselves to him.
Maybe as a member of a back-room setup, as a player development officer, head of performance or whatever, rather than the head coach, he's pretty good?
I still reflect of Richie Mathers' Tweets after he got the NRL gig -
"Not my place to. All im saying is Rich Agar is a brilliant coach, worked unbelievably hard, players loved him and ANY criticism is WAY off."
...
"Your completely entitled to your opinion but your so far off the mark. Hell of a lot of reasons but Agar 1000% wasn't one of them."